PRNP and Cognitive impairment: Accordingly, chronic caffeine treatment reduces brain Aβ levels and protects against certain synaptic plasticity deficits (Alhaider et al., 2010; Costenla et al., 2010; Alzoubi et al., 2013) and cognitive deficits in aged AD transgenic (APPsw, Swedish mutation) mice (Arendash et al., 2006, 2009; Cao et al., 2009), and protects the neuronal cells against prion protein PrP (106-126)-induced cell death by inducing autophagy (Moon et al., 2014).